G.I. Joe 2 started shooting today and Dwayne Johnson has tweeted a photo of himself as Roadblock on the 110-degree set of the sequel. Opening in theaters on June 29, 2012, the Jon Chu-directed film also stars Channing Tatum, Ray Park, Elodie Yung, RZA, DJ Cotrona, Adrianne Palicki, Ray Stevenson, Joseph Mazzello and Walton Goggins.